1. Technical Field
One or more embodiments of the present invention generally relate to ambient light emitting diode (LED) system in a vehicle.
2. Background Art
Conventional automotive ambiance lighting systems include a central controller that is electrically coupled to a plurality of LED lighting modules. The LED lighting modules may be positioned in various zones of the vehicle. Such zones may correspond to various interior and/or exterior positions of the vehicle. Each LED lighting module usually includes three or four different colored LEDs. Such colored LEDs include red, green, and blue (RGB). In some cases, white colored LEDs may be implemented along with the RGB LEDs.
The central controller includes a plurality of output drivers for driving the colored LEDs. The output drivers may generate pulse width modulated (PWM) signals and drive the colored LEDs at different PWM duty cycles to create different colors and intensities. For example, the central controller may drive the red, green, and blue LEDs with the same PWM duty cycle to produce white light. In yet another example, a purple color may be achieved by driving each of the red and blue LEDs at different PWM duty cycles. As noted above, some LED configurations may include a dedicated white colored LED as opposed to driving the red, green and blue colored LED arrangements at equal duty cycles to generate the color white. Current automotive ambient lighting systems generally couple a single wire between each output driver that is positioned in the central controller and each colored LED positioned in a lighting module. A ground or return circuit is generally coupled between the central controller and all of the LED lighting modules positioned in a particular zone of the vehicle. As such, each LED lighting module may be connected to the central controller via 4 or 5 circuits. The cost of the system is primarily dominated by the cost of the electrical wires (e.g., cut leads) and any such wire splices needed to electrical couple the cut leads. Efforts at reducing electrical wires and wire splices needed to electrically couple the cut leads are gaining more attention by vehicle manufacturers to reduce overall cost.